Based on the same bodystyles as the regular C-Class, whether you opt for the saloon, estate, coupe or convertible, there’s plenty of room up front for tall drivers, and enough width to avoid feeling cramped next to your passenger. There’s plenty of interior storage, too, with large door bins, a decent-sized glovebox and useful cubbies in the centre of the dashboard and beneath the front armrest.
There’s greater variation in rear space between the three bodystyles, though. The saloon and estate offer reasonable leg room, but head room in the saloon isn’t great for those over six feet tall. Both are rather tight on rear bench width if you want to fit three reasonably sized adults side-by-side. So, if interior space is your main requirement, we’d suggest the RS4 Avant instead.
The coupe and convertible can seat just two people in the back. Taller adults will be okay on a short trip, but will quickly become aware of the limited headroom. The convertible is tighter still, due to its very upright rear seatbacks.
Unsurprisingly, boot space is the most limited in the coupe and convertible but much better in the saloon, which can fit up to seven carry-on suitcases. The RS4 Avant has a bigger boot than the C63 Estate, but then the latter is one of the most enjoyable load-luggers on the market to drive. Usefully, the back seats fold 40/20/40 in every five-seat version of the C63 and doesn’t leave an awkward step in the extended load bay.